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Revision as of 18:50, 15 April 2008 by 204.169.63.126 (talk) (→Early papermaking in China)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff) For other uses, see Paper (disambiguation).
Paper is thin material mainly used for writing upon, printing upon or packaging. It is produced by the amalgamation of fibers, typically vegetable fibers composed of cellulose, which are subsequently held together by hydrogen bonding. While the fibers are usually natural in origin, a wide variety of synthetic fibers, such as polypropylene and polyethylene, may be incorporated into paper as a way of imparting desirable physical properties. The most common source of these kinds of fibers is wood pulp from pulpwood trees. Vegetable fiber materials such as cotton, hemp, linen, and rice are also used.
History
Papyrus and parchment
Outside Egypt, parchment or vellum, made of processed sheepskin or calfskin, replaced papyrus as the papyrus plant requires subtropical conditions to grow.
In America, archaeological evidence indicates that a similar parchment writing material was invented by the Mayans no later than the 5th century AD. Called amatl, it was in widespread use among Mesoamerican cultures until the Spanish conquest. The parchment is created by boiling and pounding the inner bark of trees, until the material becomes suitable for art and writing.
These materials are made from pounded reeds and bark and is technically not true paper, which is made from pulp, rags, and fibers of plants and cellulose.
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Papermaking arrives in the Middle East
After further commercial trading and the defeat of the Chinese in the Battle of Talas in 751, the invention spread to the Middle East. Production was started in Baghdad, where the Arabs invented a method to make a thicker sheet of paper. The manufacture had spread to Damascus by the wow meikedas a big dork.!!!!! im talkin huge. production, and it split into two centres. Cairo continued with the thicker paper. Iran became the centre of the thinner papers. It was also adopted in India.
Some historians speculate that paper was a key element in cultural advancement. According to this theory, Chinese culture was less developed than the West in ancient times prior to the Han Dynasty because bamboo, while abundant, was a clumsier writing material than papyrus; Chinese culture advanced during the Han Dynasty and subsequent centuries due to the invention of paper; and Europe advanced during the Renaissance due to the introduction of paper and the printing press.
European papermaking
The first paper mill in Europe was in Spain, at Xátiva (modern Valencia) in 1120. More mills appeared in Fabriano Italy in about the 13th century, as an import from Islamic Spain. They used hemp and linen rags as a source of fibre. The oldest known paper document in the West is the Mozarab Missal of Silos from the 11th century, probably written in the Islamic part of Spain. Paper is recorded as being manufactured in both Italy and Germany by 1400, just about the time when the woodcut printmaking technique was transferred from fabric to paper in the old master print and popular prints. The first commercially successful paper mill in England was opened by John Spilman in 1588 near Dartford in Kent and was initially reliant on German papermaking expertise.
Applications
- To write or print on: the piece of paper becomes a document; this may be for keeping a record (or in the case of printing from a computer or copying from another paper: an additional record) and for communication; see also reading.
Paper can be produced with a wide variety of properties, depending on its intended use.
- To represent a value: paper money, bank note, cheque, security (see Security paper), voucher and ticket
- For entertainment: book, magazine, newspaper, art, zine,
- For packaging: corrugated box, paper bag, envelope, wrapping tissue, Charta emporetica and wallpaper
- For cleaning: toilet paper, handkerchiefs, paper towels, facial tissue and cat litter
- For construction: papier-mâché, origami, quilling, Paper honeycomb, used as a core material in composite materials, paper engineering, construction paper and clothing
- Other uses: emery paper, sandpaper, blotting paper, litmus paper, universal indicator paper, paper chromatography and Capacitor Dielectrics (Permittivity 1.5 - 3)
Types and weight
Paper is often characterized by weight. The weight assigned to a paper is the weight of a ream, 500 sheets, of varying "basic sizes", before the paper is cut into the size it is sold to end customers. For example, a ream of 20 lb, 8½ x 11" paper weighs 5 pounds, because it has been cut from a larger sheet into four pieces. In the United States, printing paper is generally 20 lb, 24 lb, or 32 lb at most. Cover stock is generally 68 lb, and 110 lb or more is considered card stock.
In Europe the weight is expressed in grammes per square metre (gsm or usually just g) of the paper. Printing paper is generally between 60g and 120g. Anything heavier than 160g is considered card. The weight of a ream with therefore depends on the dimensions of the paper; One ream of A4 (210mm x 297mm) size (approx 8.27" x 11.7") weighs 2.5 kilogrammes (approx 5.5 pounds).
The density of paper ranges from 250 kg/m (16 lb/ft) for tissue paper to 1500 kg/m (94 lb/ft) for some speciality paper. Printing paper is about 800 kg/m (50 lb/ft).
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The future of paper
Some manufacturers, notably AMD, have started using a new, significantly more environmentally friendly alternative to expanded plastic packaging made out of paper, known commercially as paperfoam. The packaging has very similar mechanical properties to some expanded plastic packaging, but is biodegradable and can also be recycled with ordinary paper.
With increasing environmental concerns about synthetic coatings (such as PFOA) and the higher prices of hydrocarbon based petrochemicals, there is a focus on zein (corn protein) as a coating for paper in high grease applications such as popcorn bags.
Besides paperfoam, paper made from rocks rather than trees is also emerging as a more ecological alternative to regular paper made from trees or other alternatives as paperfoam. This Rock paper is available from companies as ViaStone and John Su.
Invisible paper is being developed by Gaskell Industries Ltd., to be used as a substitute to more visible alternatives.
Also, synthetics such as Tyvek and Teslin have been introduced as printing media as a more durable material than paper.
References and Notes
- The Construction of the Codex In Classic- and post classic-Period Maya Civilization Maya Codex and Paper Making
- Meggs, Philip B. A History of Graphic Design. John Wiley & Sons, Inc. 1998. (pp 58) ISBN 0-471-291-98-6
- "Grades and uses of paper". Retrieved 2007-10-12.
- McKenzie, Bruce G., The Hammermill Guide to Desktop Publishing in Business, p. 144, Hammermill Papers, 1989.
- "Density of paper and paperboard". PaperOnWeb. Retrieved 2007-10-31.
- Rock paper emerging as ecological alternative
- John Su distributing rock paper
- ViaStone distributing rock paper
- Needham, Joseph (1986). Science and Civilization in China: Volume 5, Chemicals and Chemical Technology, Part 1, Paper and Printing. New York: Cambridge University Press, 1985. (also published in Taipei: Caves Books, Ltd., 1986.)
- also referred to as:
- Tsien, Tsuen-Hsuin, '"Paper and Printing," vol. 5 part 1 of Needham, Joseph Science and Civilization in China:. Cambridge University Press, 1986. ISBN 0521086906. (also published in Taipei: Caves Books, Ltd., 1986.)
- "Document Doubles" in Detecting the Truth: Fakes, Forgeries and Trickery, a virtual museum exhibition at Library and Archives Canada
See also
External links
- TAPPI Technical Association of the Pulp and Paper Industry
- How is paper made? at The Straight Dope, 22 November 2005
- How Paper Is Made
- United States Government Printing Office: Government Paper Specification Standards
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